Borrelia miyamotoi

Fact sheet on Borrelia miyamotoi

What is Borrelia miyamotoi?

Borrelia miyamotoi is a bacterium (germ) that can be spread by infected black-legged (deer) ticks. These bacteria have only recently been discovered as a cause of some human illness.

How is Borrelia miyamotoi spread?

Borrelia miyamotoi is spread by the bite of an infected black-legged tick. These ticks in Massachusetts can also carry the germs that cause babesiosis, human granulocytic anaplasmosis, lyme disease, and Powassan virus. Black-legged ticks can spread more than one type of germ in a single bite.

What are the symptoms of Borrelia miyamotoi infection?

Symptoms of Borrelia miyamotoi infection generally include fever or chills, headache, and muscle aches.  Less common symptoms include fatigue, rash, abdominal cramps, nausea, vomiting, diarrhea, dizziness, and confusion.

How soon do symptoms of Borrelia miyamotoi appear?

Symptoms of Borrelia miyamotoi usually begin to appear on average two weeks after being bitten by an infected tick, though it can range from 3 days to 6 weeks. 

How is Borrelia miyamotoi infection diagnosed?

Borrelia miyamotoi infection is diagnosed through laboratory testing including molecular (PCR) and/or serologic tests.

How is Borrelia miyamotoi treated?

Infection with Borrelia miyamotoi can be treated with antibiotics.

Where does Borrelia miyamotoi occur?

Borrelia miyamotoi was identified in black-legged ticks in New England in 2001 and has also been found in these ticks in the Great Lakes region and in similar ticks in California. In Massachusetts, Borrelia miyamotoi occurs throughout the state.

Is there a seasonality (time of year) one is more likely to get Borrelia miyamotoi?

Cases of Borrelia miyamotoi can occur any time ticks are active. Young ticks (nymphs) are most active during the warm weather months between May and July. Adult ticks are most active during the fall and spring but will also be out searching for a host any time that temperatures are above freezing.

How can you prevent Borrelia miyamotoi infection?

Prevention begins with you! Take steps to reduce your chances of being bitten by any tick. Ticks are most active during warm weather, late spring through fall. However, ticks can be out any time that temperatures are above freezing. Ticks cling to vegetation and are most numerous in brushy, wooded, or grassy habitats. When you are outside in an area likely to have ticks (e.g., brushy, wooded, or grassy places), follow these simple steps to protect yourself and your loved ones:

• Use EPA registered tick repellents.
• Products with DEET may be used on skin. Repellents containing DEET should not be used on children less than 2 months of age and should be used in concentrations no higher than 30% on older children.
• Use permethrin products on items such as clothing, shoes, bed nets and camping gear. Permethrin should not be applied to skin.
• Other repellents, such as picaridin, oil of lemon eucalyptus and IR 3535, have also been found to provide protection against ticks. More information on choosing a repellent and how to use repellents safely is included on the DPH Public Health Fact Sheet on Tick Repellents at mass.gov/DPH/Ticks.
• Wear long, light-colored pants tucked into socks or boots, and a long-sleeved shirt. This will help keep ticks away from your skin and help you spot a tick on your clothing faster.
• Stay on trails when walking or hiking, avoiding the edge habitat where ticks are likely to be.
• Talk to your veterinarian about tick control options (tick collars, repellents) for your pets.

After spending time in an area likely to have ticks, check yourself, your children, and pets for ticks. Young ticks, called nymphs, are the size of a poppy seed. Adult ticks are the size of a sesame seed. Both nymph and adult ticks can spread diseases; however, nymphs are more of a concern. They are aggressive feeders and so tiny that it can be difficult to see them on the body unless you look carefully. When doing a tick check, remember that ticks like places that are warm and moist. Always check the back of the knees, armpits, groin, scalp, back of the neck and behind the ears. If you find a tick attached to your body, remove it as soon as possible using fine-point tweezers. Do not squeeze or twist the tick’s body, instead grasp it close to your skin and pull straight out with steady pressure.

Know the symptoms of tick-borne disease.  If you have been someplace likely to have ticks and develop symptoms of any disease carried by ticks, see your health care provider right away.

Where can I get more information on Borrelia miyamotoi?

• For questions about your own health, contact your health care provider.
• For questions about diseases spread by ticks, contact DPH at [phone] or online at mass.gov/DPH/Ticks. You may also contact your local Board of Health.
• Health effects of pesticides, DPH, Bureau of Climate and Environmental Health at [phone].